2171990437265 has 32 divisors (see below), whose sum is σ = 2904264599040. Its totient is φ = 1545788563200.

The previous prime is 2171990437237. The next prime is 2171990437277. The reversal of 2171990437265 is 5627340991712.

It is a happy number.

It is not a de Polignac number, because 2171990437265 - 2³⁴ = 2154810568081 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2171990437265.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18213935 + ... + 18332795.

It is an arithmetic number, because the mean of its divisors is an integer number (90758268720).

Almost surely, 2^{2171990437265} is an apocalyptic number.

It is an amenable number.

2171990437265 is a deficient number, since it is larger than the sum of its proper divisors (732274161775).

2171990437265 is a wasteful number, since it uses less digits than its factorization.

2171990437265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125993.

The product of its (nonzero) digits is 5715360, while the sum is 56.

The spelling of 2171990437265 in words is "two trillion, one hundred seventy-one billion, nine hundred ninety million, four hundred thirty-seven thousand, two hundred sixty-five".